Aristotle, Copernicus, Bruno: centrality, the principle of movement and the extension of the Universe

This paper¹ studies the different conceptions of both centrality and the principle or starting point of motion in the Universe held by Aristotle and later on by Copernicanism until Kepler and Bruno. According to Aristotle, the true centre of the Universe is the sphere of the fixed stars. This is also the starting point of motion. From this point of view, the diurnal motion is the fundamental one. Our analysis gives pride of place to De caelo II, 10, a chapter of Aristotle’s text which curiously allows an ‘Alpetragian’ reading of the transmission of motion.In Copernicus and the Copernicans, natural centrality is identified with the geometrical centre and, therefore, the Sun is acknowledged as the body through which the Deity acts on the world and it also plays the role of the principle and starting point of cosmic motion. This motion, however, is no longer diurnal motion, but the annual periodical motion of the planets. Within this context, we pose the question of to what extent it is possible to think that, before Kepler, there is a tacit attribution of a dynamic or motive role to the Sun by Copernicus, Rheticus, and Digges.For Bruno, since the Universe is infinite and homogeneous and the relationship of the Deity with it is one of indifferent presence everywhere, the Universe has no absolute centre, for any point is a centre. By the same token, there is no place that enjoys the prerogative of being—as being the seat of God—the motionless principle and starting point of motion.     

Effects of the metals,Be, Fe,Cu and Al,on the mobility of immunoglobulin receptors

Summary Cap formation in mouse spleen cells induced by antiimmunoglobulin was inhibited by the metals Be, Fe, Cu and Al. Be was especially strong as an inhibitor of cap formation. It is suggested that these metals might change the mobility of the membrane and have some biological effects on the cross association of antigen receptors when B lymphocytes are attached by them.     

The cosmological constant, the fate of the universe, unimodular gravity, and all that

The cosmological constant is back. Several lines of evidence point to the conclusion that either there is a positive cosmological constant or else the universe is filled with a strange form of matter (“quintessence”) that mimics some of the effects of a positive lambda. This paper investigates the implications of the former possibility. Two senses in which the cosmological constant can be a constant are distinguished: the capital Λ sense in which lambda is a universal constant on a par with the charge of the electron, and the lower case λ sense in which lambda is a humble constant of integration. The latter interpretation has been touted as the means to a solution to various problems in physics. These claims are critically examined with an eye to discerning the implications for philosophy of science and foundations of physics.     

Thermoscopes, thermometers, and the foundations of measurement

Psychologists debate whether mental attributes can be quantified or whether they admit only qualitative comparisons of more and less. Their disagreement is not merely terminological, for it bears upon the permissibility of various statistical techniques. This article contributes to the discussion in two stages. First it explains how temperature, which was originally a qualitative concept, came to occupy its position as an unquestionably quantitative concept (§§1–4). Specifically, it lays out the circumstances in which thermometers, which register quantitative (or cardinal) differences, became distinguishable from thermoscopes, which register merely qualitative (or ordinal) differences. I argue that this distinction became possible thanks to the work of Joseph Black, ca. 1760. Second, the article contends that the model implicit in temperature’s quantitative status offers a better way for thinking about the quantitative status of mental attributes than models from measurement theory (§§5–6).     

Cosmology,particles, and the unity of science

During the last three decades, there has been a growing realization among physicists and cosmologists that the relation between particle physics and cosmology may constitute yet another successful example of the unity of science. However, there are important conceptual problems in the unification of the two disciplines, e.g. in connection with the cosmological constant and the conjecture of inflation. The present article will outline some of these problems, and argue that the victory for the unity of science in the context of cosmology and particle physics is still far from obvious.     

The Protection of the anemone fish,Amphiprion xanthurus,from the sea anemone,Stoichactis kenti

Zusammenfassung Reziproke Kombinationsversuche zeigen, dass «angewöhnte» Anemonenfische nicht von Seeanemonen genesselt werden, die der gleichen Art angehören, mit der sie zusammengelebt haben. Nicht angewöhnte Fische werden durch Seeanemonen gensselt unabhängig, ob letztere angewöhnte Fische beherbergen oder nicht. Wird die Oberfläche angewöhnter Fische abgewischt, verliert sie ihren Schutz 9.     

Neurosecretory cells of the globuli I and the protocephalic neurosecretory pathway of the myriapods, diplodods. Preliminary observations on the Polydesmida, Platyrrhacidae, the Nematophora Lysiopetalidae, the Spirostreptida and the Spirobolida]

The Diplopods studied by the author and more particularly Platyrrhacidae, Lysiopetalidae, Spirostreptida and Spirobolida, show neurosecretory cells near the globuli I. The whole of his observations induces the author to admit a structural plan common to all the Diplopods: neurosecretory cells of globuli I--(NOG) nerve--neurohemal organ (Gabe's organ). Moreover he makes an attempt to compare his observations with those concerning another group of Myriapods: the Chilopods.     

On the genesis of the soil mantle of the region of Manaus,Central Amazonia,Brazil

Summary The dynamics of the forest to the north of Manaus is tightly linked to that of the soil. The latosol that covers the plateau, which supports a dense forest, consists from top to bottom of: (a) a brown, clayey organic horizon (0.3 m), (b) a yellow horizon, very rich in clay but permeable (from 0.3 to 4 m), (c) a nodular horizon rich in Al and Fe oxides (from 4 to 9 m), and (d) a horizon which still preserves the sedimentary structures of the parent sandstone, where quartz is intensely dissolved and kaolinite crystallizes in pores. In perfectly flat areas, the clay of the organic horizon is destroyed by acidocomplexolysis, and the dissolved Al is transported vertically by the drainage water. A part of this Al is used to make the gibbsite nodules of horizon (c), and the rest is used to make kaolinite in horizon (d). Because aluminum is thus conserved within any vertical prism, the rate of destruction of horizon (a) is equivalent to the rate of advance of the kaolinization zone into the sediment: the latosol is said to be in equilibrium, the surface remains perfectly flat as it slowly sinks, the quantity of kaolinite increases with time, and the silica released by quartz dissolution in the whole profile is exported by drainage water to the water table. In contrast, near drainage axes, however small initially, the drainage becomes inclined toward the axis. Part of the Al released by acidocomplexolysis of horizon (a) is now exported to rivers, and Al is no longer conserved within any given prism. The rate of advance of the kaolinization zone (d) into the sediment now becomes less than the rate of destruction of horizon (a) and the surface sinks faster than that of the surrounding plateau. After this differential podzolization has gone on long enough, it creates a network of geochemical valleys characterized by convex slopes and bounded by sandy soils (campinas). The vegetation becomes sparser and sparser. At the end, only some bushes and lichens survive on the white sand.Acknowledgments. The authors are indebted to Dr E. Merino (Dept. of Geology, Indiana University) for helpful criticisms and suggestions. This research was carried out in I.N.P.A. (Instituto Nacional de Pesquisas da Amazonia) and was financially supported by the CNPq-CNRS/ORSTOM conv.     

Giffordene, 2Z, 4Z, 6E, 8Z-undecatetraene,is the odoriferous principle of the marine brown algaGiffordia mitchellae

Summary Giffordene, 2Z, 4Z, 6E, 8Z-undecatetraene, and five stereoisomers are new odoriferous C₁₁H₁₆-hydrocarbons from the marine brown algaGiffordia mitchellae. Their isolation and identification is described.Acknowledgments. We thank Prof. G. Ohloff for kindly providing us with synthetic 1,3,5,7-undecatetraenes and Prof. P. Schreier for GC/FTIR-analyses.